JPH0131799Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a variable inertia mass type flywheel device that suppresses fluctuations in the output torque of the output shaft of an engine.

In general, in internal combustion engines such as gasoline engines and diesel engines, the only stroke that produces output is the explosion stroke, and the exhaust, intake, and compression strokes consume power, so the rotation of the crankshaft is difficult to smooth.

Therefore, attempts have been made to increase the number of cylinders and combine the strokes of each cylinder evenly, but this alone is not sufficient, so a flywheel 2 is attached to the rear end of the crankshaft 1 as shown in Figure 1. The sudden rotational force of the explosion stroke is stored in the flywheel 2, and rotation is made smooth during the other strokes.

By the way, the conventional flywheel 2 is disc-shaped, and for example, the flywheel 2 is often made thicker at the circumference to increase the inertia as much as possible and to reduce the weight. There is. However, in the conventional configuration described above, the weight of the flywheel 2 was constant, so when the weight of the flywheel 2 is relatively large, it is easy to suppress fluctuations in the output torque in the low rotation range of the engine. Although stability can be improved, when the engine speed is accelerated, the inertia force due to the rotation of the flywheel 2 acts as resistance, so there is a problem that it is difficult to improve acceleration performance, and when the engine speed is decelerated, the engine There was also the problem that the braking effect of the brakes deteriorated. For this reason, the flywheel is composed of a main flywheel and a sub flywheel, and the sub flywheel is separated in the high engine speed range to reduce the inertial mass of the flywheel and improve acceleration performance and the braking effect of the engine brake during deceleration. What has been done is considered. However, the electronically controlled fuel injection system cuts off or reduces the fuel supply when the engine speed exceeds a predetermined speed A and the auxiliary flywheel is disconnected, and then the accelerator pedal is released and the engine brake is activated. ing. Then, when the engine speed falls between the predetermined speed A and a smaller predetermined speed B, the gas pedal is depressed again, and the fuel supply is restarted, but the inertial mass is small. If left as is, the engine rotational fluctuations would be large and the output torque would fluctuate easily, resulting in a lack of stability.

This idea was made in view of the above points, and its purpose is to prevent fluctuations in engine rotation when fuel supply from the electronically controlled fuel injection device is resumed, and to suppress fluctuations in output torque and stabilize it. An object of the present invention is to provide a variable inertia mass type flywheel device that can improve performance.

This invention will be described below with reference to embodiments shown in the drawings. 2 to 4 show an embodiment of this invention, and 11 is a crankshaft (output shaft) of the engine. A main flywheel 12 is connected to the rear end of the crankshaft 11. The main flywheel 12 is a disc-shaped member, and its central portion is attached to the rear end surface of the crankshaft 11 via an attachment 14 with a plurality of bolts 13 . Furthermore, a bent edge 15 is formed on the outer circumference of the main flywheel 12 and is bent inward. An inclined surface 16 is formed at the base end of the inner surface of the bent edge 15, and a ring gear is provided on the outer peripheral surface of the bent edge 15. Further, a sub flywheel 17 is provided inside the main flywheel 12 so as to face the main flywheel 12. This sub-flywheel 17 is a substantially ring-shaped member, and one end surface side of this sub-flywheel 17 has a bent edge 15 of the main flywheel 12.
A ring-shaped guide groove 19 is formed on the insertion portion 18 to be inserted into the inner side of the insertion portion 18 and the other end surface thereof. Furthermore, a ring-shaped protrusion 21 is formed on the inner circumferential surface 20 of the sub-flywheel 17, and a ring-shaped elastic body 22 made of heat-resistant rubber or the like is formed on the main flywheel 12 side of the protrusion 21. The outer peripheral surface is fixed by baking or other means. Further, the inner peripheral surface of this elastic body 22 is fixed to the outer peripheral surface of a cylindrical support member 23 by means such as baking. This support member 23 is rotatably attached to the outer peripheral surface of an attachment 14 at the rear end of the crankshaft 11 via a ball bearing 24. Further, a spring receiver 26 is attached to the end surface of the supporting member 23 on the side opposite to the main flywheel 12 side by a plurality of bolts 25 . Furthermore, a disc spring (spring member) is provided between the spring receiver 26 and the convex portion 21 of the sub flywheel 17.
27 is disposed, and the biasing force of the disc spring 27 keeps the sub flywheel 17 pressed against the main flywheel 12 at all times. Note that the insertion portion 18 of the sub flywheel 17
An inclined surface 28 facing the inclined surface 16 of the main flywheel 12 is formed on the outer peripheral edge of the tip of the main flywheel 12. A contact body 29 such as a clutch facing material is attached to this inclined surface 28, and this contact body 29 is attached to the inclined surface 28. The main flywheel 12 and the sub flywheel 17 come into contact with each other via the body 29. Further, the tip of an electromagnet (operating section) 30 is inserted into the guide groove 19 of the sub flywheel 17, and when the electromagnet 30 is not energized, the sub flywheel 17 is attached to the disk spring 27. It is held in a state where it is pressed against the main flywheel 12 side by force. Therefore, the sub flywheel 17 is connected to the main flywheel 12, and as the crankshaft 11 rotates, both the main and sub flywheels 12, 17 rotate integrally. This electromagnet 30
The base end portion of is attached to a fixed portion such as the crankcase 31, for example.

Next, FIG. 3 shows a control circuit, and the electromagnet 30 shown in FIG. 2 is turned on and off by a control circuit 32 such as a microcomputer.
It is starting to be turned off. This control section 32
A rotation speed detection circuit 33 for detecting the rotation speed of the engine is connected to the rotation speed detection circuit 33.
The detection signal from is input to the control section 32.
Further, 34 is a throttle valve OFF detection circuit that detects whether the throttle valve is closed and outputs a detection signal to the control section 32, and 35 is a throttle valve OFF detection circuit that detects whether the throttle valve is closed or not and outputs a detection signal to the control section 32. A fuel cut signal detection circuit detects a fuel cut signal to be stopped and outputs the detection signal to the control section 32, and 36 is a fuel cut end signal outputted from the electronically controlled fuel injection device when canceling the stop of fuel supply. This is a fuel cut end signal detection circuit that detects a fuel cut end signal and outputs the detection signal to the control section 32.

Next, the operation of this device configured as described above will be explained. The control unit 32 controls the engine rotation speed and throttle valve input from the rotation speed detection circuit 33.
A detection signal inputted from the OFF detection circuit 34 to detect whether the throttle valve is closed, a detection signal inputted from the fuel cut signal detection circuit 35 when a fuel cut signal to stop fuel supply is detected, and a fuel cut end. Based on the detection signal when the fuel cut end signal inputted from the signal detection circuit 36 is detected, the process shown in the flowchart shown in FIG. changing mass. The operation will be described below with reference to the flowchart shown in FIG. First, in step S1, it is determined that the engine speed is below B (for example, 1000 rpm).
If it is determined to be "ON" in this step S1, the process proceeds to step S2, where it is determined whether the engine speed is equal to or higher than A (for example, 1500 rpm). If the determination in step S2 is ``YES'', the process proceeds to step S3, where a flag Z in a predetermined memory area of the control section 32 is set. Next, the process proceeds to step S4, where it is determined whether the sub flywheel 17 is separated from the main flywheel 12. If the determination in step S4 is "NO", the process proceeds to step S5 and the electromagnet 30 is energized. When this electromagnet 30 is energized, the sub flywheel 17 is attracted to the electromagnet 30, and the sub flywheel 17 moves to the left in FIG. 2 against the biasing force of the disc spring 27. Therefore, since the sub flywheel 17 is separated from the main flywheel 12, only the main flywheel 12 rotates as the crankshaft 11 rotates. Therefore, when the engine speed is A or higher, the crankshaft 11
Since the inertial mass generated in the engine can be reduced, it is possible to improve the acceleration performance in the high rotation range and the braking effect of the engine brake.

On the other hand, if the answer in step S2 is NO, that is, if the engine speed is greater than B and smaller than A, the process proceeds to step S6, where it is determined whether or not the flag Z is set. When this flag Z is set, it indicates that the sub flywheel 17 is separated from the main flywheel 12. In other words, it means that the engine speed once exceeded A and then dropped to a speed smaller than A and larger than B. Furthermore, the process proceeds to step S7, where it is determined whether flag Y is set. In this case, the determination is "NO" and the process proceeds to step S8. This step S
At 8, it is determined whether the throttle valve is closed. "YES" in this step S8
If it is determined that this is the case, the process advances to step S9. In step S9, it is determined whether the supply of fuel from the electronically controlled fuel injection device is stopped. If the determination in step S9 is ``YES'', the process proceeds to step S10, where a flag Y is set in a predetermined memory area of the control section 32. Then, the process returns to step S1. And the engine speed is A
If it is smaller than B, proceed to step S above.
1, the determination is "NO", and the determination in step S2 is "NO". Then, in step S7, it is determined whether flag Y is set. In this case, the determination is ``YES'' and the process advances to step S11. In step S11, it is determined whether or not the stoppage of fuel supply by the electronically controlled fuel injection device has been released. This step S11
If it is determined as "YES" in the step, the sub flywheel 17 is rotated at a speed corresponding to the rate of change of the engine speed.
The electromagnet 30 is gradually de-energized so that it is connected to the main flywheel 12. In other words, the sub flywheel 17 is held pressed against the main flywheel 12 by the biasing force of the disc spring 27. Therefore, the sub flywheel 17 is connected to the main flywheel 12, and as the crankshaft 11 rotates, both the main and sub flywheels 12, 17 rotate integrally, increasing the inertial mass generated in the crankshaft 11. be able to. Therefore, it is possible to prevent engine rotational fluctuations when fuel supply is restarted in the electronically controlled fuel injection device, and it is possible to suppress fluctuations in output torque and improve stability. After the processing in step S12 is completed, flags Y and Z are reset in step S13, and the process returns to step S1.

If the determination in step S1 is ``YES'', the process advances to step S14, where it is determined whether or not the sub flywheel 17 is connected to the main flywheel 12. If the determination in step S14 is "NO", the process proceeds to step S15, where the electromagnet 30 is de-energized, the sub flywheel 17 is connected to the main flywheel 12, and the inertial mass generated in the crankshaft 11 is increased. be done. Therefore, fluctuations in the output torque in the low engine speed range can be effectively suppressed, and driving stability and fuel efficiency can be improved. When the process of step S15 is completed, the process returns to the process of step S1.

As detailed above, according to this invention, it is possible to prevent fluctuations in engine rotation when fuel supply from the electronically controlled fuel injection device is resumed, suppress fluctuations in output torque, and improve stability. It is possible to provide a variable inertia mass type flywheel device that can perform

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional flywheel.
Figures 2 to 4 show an embodiment of this invention, with Figure 2 being a vertical sectional view of the main parts, Figure 3 being a schematic configuration diagram showing the control section, and Figure 4 explaining the operation. This is a flowchart for 11...Crankshaft (output shaft), 12...
... Main flywheel, 17 ... Sub-flywheel, 30 ... Electromagnet (operation section), 32 ... Control section,
33...Rotational speed detection circuit, 34...Throttle valve OFF detection circuit, 35...Fuel cut signal detection circuit, 36...Fuel cut end signal detection circuit.

Claims (1)

[Scope of utility model registration request] A flywheel whose inertial mass can be varied by connecting or separating a main flywheel connected to an output shaft of an engine and a sub-flywheel provided opposite to the main flywheel; An operating section that operates in the direction of separation, a rotation speed detection circuit that detects the engine rotation speed, a throttle valve off detection circuit that detects whether the throttle valve is closed, and an output from the electronically controlled fuel injection device. A fuel cut signal detection circuit that detects a fuel cut signal to stop fuel supply, and a fuel cut end signal detection circuit that detects a fuel cut end signal output from an electronically controlled fuel injection device when canceling the stop of fuel supply. , the engine speed is determined to be greater than or equal to B and less than or equal to A (A>B) by the rotational speed detection circuit, the throttle valve off detection circuit detects that the throttle valve is closed, and the fuel cut signal detection circuit detects that the throttle valve is closed. When it is detected that the fuel supply has been stopped and the fuel cut end signal detection circuit detects that the fuel supply stop has been canceled, the operation section connects the sub flywheel to the main flywheel. A variable inertia mass type flywheel device, comprising: a control unit that switches the main flywheel and the sub flywheel to a rotating state.